992 resultados para FT-RS


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The interactions of lanthanide ions with sphingomyelin bilayers have been studied by using 2D NOESY spectroscopy and FT-Raman spectroscopy methods. The results indicate that lanthanide ions, as well as divalent calcium, combine mainly to the phosphate group in the polar headgroup and do not change the conformation of O-C-C-N+ backbone in the choline group of sphingomyelin bilayers. The polar headgroup is still extending parallel to the bilayer surface and O-C-C-N+ group is still in its gauche conformer.

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The interaction of trivalent lanthanide ions and divalent calcium ions with sphingomyelin bilayer has been studied by FT-Raman spectroscopy. The results showed that the bonding of metal ions to the phosphate group of sphingomyelin bilayer, either La3+ or Ca2+, did not change the conformation of the choline group, that is, O-C-C-N+ is still in its gauche conformation. The presence of metal ions changed the states of the interfacial region from liquid-like to amorphous state and even to crystalline. They increased the fluidity of acyl chains of sphingomyelin bilayer and made them packed disorderly.

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The effects of lanthanide ions and their complexes of citrate and DTPA ligands on the fluidity of dipalmitoylphosphatidylethanolamine (DPPE) bilayers have been studied by FT-Raman spectroscopy. the results show that lanthanide ions of lower concentrationn decrease the fluidity of acyl chains of DPPE bilayers and change the conformation of C C-C backbone from gauche to the trans lanthanide ions of higher concentration, however, increase the fluidity of acyl chains and increase the gauche population of C-C-C backbone. Lanthanide complex of citrate have no effect on the fluidity of acyl chains of DPPE bilayers in the region of experimental concentration, but La-DTPA complex increase slightly the fluidity of acyl chains. the results also indicated that lanthanide ion of lower concentration changed the lattice packing of hydrocarbon chains from hexagonal form to orthorhombic form, but it is still in hexagonal or distorted hexagonal lattice cell in the gel state in the presence of metal ions and lanthanide complexes of higher concentration

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FT-Raman光谱研究镧与胆固醇对二棕榈酰磷脂酰甘油脂双层的作用吴英,李新民,赵冰,徐蔚青,陶艳春,赵大庆,倪嘉缵(吉林大学分子光谱与分子结构开放实验室长春130023)中国科学院长春应用化学研究所稀土化学与物理开放实验室长春130022)FT-R...

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嵌段高聚物、均聚物共混体系相容性是近年来研究的热点。本工作以光学显微镜、DSC、FT-IR为手段,研究了三嵌段高聚物苯乙烯-丁二烯-苯乙烯(SBS);SBS-48、SBS-30,SBS-28与聚乙烯基甲基醚共混体系的相容性。DSC结果表明,随SBS中PS含量的升高,体系相容性变好,PS段分子量增大,也有助于体系相容。FT-IR结果表明PVME中COCH_3在1100cm~(-1)附近呈现的双峰的相对强度对体系的相容性十分敏感,而由于苯环C—H振动产生的698cm~(-1)峰位却不象PS/PVME体系那样随相容性的改变而有显著的改变。总而言之,嵌段高聚物SBS/均聚物PVME共混体系中,体系的相容性依赖于嵌段高聚物在体系中的组份含量及嵌段高聚物中PS的重量百分含量,PS段分子量的大小对体系相容性也有影响。

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阐述了具有自动导引车(AGV)和自动存取系统(AS/RS)的物流系统的工作流程,建立了该类物流系统的排队网络模型,分析了系统的性能与系统设计参数之间的关系,为设计具有AGV和AS/RS的复杂物流系统提供依据。

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提出了一种基于信道估计的RS纠错编码改进算法,该算法可以自适应地根据外界条件和环境对传输信道的干扰变化实时地调节编码系统的数据冗余量。仿真与完整的分析结果证实了该改进算法有效地改善了RS编码算法的传输效率;并且通过实际应用表明:良好的性能,高容错性适应于该通信系统的多种传输信道,具有很强的实用性。

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喀斯特石漠化( Karst Rocky Desertification , KRD) 是指喀斯特区地表出现类似荒漠景观的土地退化过程。采用RS 和GIS 技术,对都安喀斯特石漠化程度分级状况与驱动因素进行全面调查,建立全县1∶1 0 万喀斯特石漠化数据库。利用相关分析、因子分析和回归分析等方法,分析导致石漠化的影响因子,即喀斯特石漠化的重要驱动力,建立了喀斯特石漠化动力指数模型,算出了各因子对石漠化的贡献值,指出石漠化产生的主导原因是不合理的人为活动。所建的动力指数模型输出结果与遥感调查有相对一致性,表明石漠化动力指数能较好地反映该地区石漠化过程,可为喀斯特石漠化治理提供理论依据。

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依托GIS与RS技术,以广西省都安瑶族自治县为研究载体,采用TM影像为背景资料.辅以地形图、土地利用图、地质图、土壤图以及GPS实测数据库等相关资料综合分析,建立石漠化分级的遥感影像解译指标体系,生成都安县石漠化分级分布图和数字化土壤类型图;运用GIS空间分析功能.定量探讨不同级别石漠化与土壤类型之间的空间相互关系。

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本文以岩溶山区贵阳市为研究对象,利用多时相TM遥感数据及相关资料,结合地理信息系统技术,对贵阳市资源环境进行了初步调查与研究。论文研究内容主要包括三个部分:(1)遥感图象予处理(2)遥感图象分类(3)试验区空间数据库的建立与初步应用。通过本论文的研究,得到以下几点认识和成果:a)在岩溶山区城市能利用TM数据城市环境调查与动态研究。b)探索了一个适合于岩溶山区城市TM遥感土地分类的最佳波段组合。c)通过对TM数据土地分类结果分析。认为试验区土地利用结构不合理。d)制作了试验区一系列不同时相的遥感专题数据图件。通过这些专题图件可以得到试验区的资源环境现状及其变化趋势。e)建立了试验区实间数据库。

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本文探讨了遥感(RS)和地理信息系统(GIS)在岩溶地区水文模型中的应用情况,并结合中国-比利时政府间国际合作项目“遥感和水文模式技术在岩溶地区土地和水资源管理的应用“部分研究内容,成功地将RS,GIS应用到岩溶地区的水文模型研究中去,并到得了一系列十分有意义的成果。这是首次在国内开展这类工作,在国外将RS,GIS应用到岩溶地区的水文模型研究工作也十分鲜见,固而说论文获取的成果对岩溶地区的科研工作具有重要意义。对生产管理工作也是如此。

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Adsorption and oxidation of chlorobenzene on Al(2)O(3), TiO(2)-Al(2)O(3), and MnO(x)/TiO(2)-Al(2)O(3) have been studied by in situ Fourier transform infrared (FT-IR) spectroscopy. At room temperature, chlorobenzene is only physisorbed on Al(2)O(3), TiO(2)-Al(2)O(3), and MnO(x)/TiO(2)-Al(2)O(3), and gives the same IR spectrum as that for liquid-phase chlorobenzene. On Al(2)O(3) no further interaction and reaction take place with treatment, at higher temperatures (up to 773 K), while phenolates are observed for TiO(2)-Al(2)O(3) and MnO(x)/TiO(2)-Al(2)O(3) at 773 K. When the adsorbed chlorobenzene coexists with oxygen, formates are detected for Al(2)O(3), while acetates are additionally observed for TiO(2-)Al(2)O(3) above 573 K. For MnO(x)/TiO(2-)Al(2)O(3), maleates are present at 573 And 673 K, while formates and acetates develop at 473 and 573 K. Almost all IR bands due to formates, acetates, and maleates disappear at 773 K, indicating that these oxygen-containing species are potential intermediates for the total oxidation of chlorobenzene.